Category : OS/2 Files
Archive   : ZOO21E.ZIP
Filename : DECODE.C

/*$Source: /usr/home/dhesi/zoo/RCS/decode.c,v $*/
/*$Id: decode.c,v 1.6 91/07/09 01:39:49 dhesi Exp $*/
/***********************************************************
decode.c

Adapted from "ar" archiver written by Haruhiko Okumura.
***********************************************************/

#include "options.h"
#include "zoo.h"
#include "ar.h"
#include "lzh.h"

extern int decoded; /* from huf.c */

static int j; /* remaining bytes to copy */

void decode_start()
{
huf_decode_start();
j = 0;
decoded = 0;
}

/*
decodes; returns no. of chars decoded
*/

int decode(count, buffer)
uint count;
uchar buffer[];
/* The calling function must keep the number of
bytes to be processed. This function decodes
either 'count' bytes or 'DICSIZ' bytes, whichever
is smaller, into the array 'buffer[]' of size
'DICSIZ' or more.
Call decode_start() once for each new file
before calling this function. */
{
static uint i;
uint r, c;

r = 0;
while (--j >= 0) {
buffer[r] = buffer[i];
i = (i + 1) & (DICSIZ - 1);
if (++r == count)
return r;
}
for ( ; ; ) {
c = decode_c();
if (decoded)
return r;
if (c <= UCHAR_MAX) {
buffer[r] = c;
if (++r == count)
return r;
} else {
j = c - (UCHAR_MAX + 1 - THRESHOLD);
i = (r - decode_p() - 1) & (DICSIZ - 1);
while (--j >= 0) {
buffer[r] = buffer[i];
i = (i + 1) & (DICSIZ - 1);
if (++r == count)
return r;
}
}
}
}